Toll like receptor-based electrochemical sensors via N-heterocyclic carbene-modified surfaces: towards improved sensing of DNA molecules

Pathogen detection on gold surfaces using N-heterocyclic carbenes (NHCs) functionalized with amine tags along with an organic linker, bis(sulfosuccinimidyl)suberate sodium salt (BS3) to chemically bind toll-like receptor 9 (TLR9) to gold electrodes, is reported here for the first time. TLRs are essential components of the early warning system of the human innate immune response, with TLR9 being a DNA sensing receptor that specifically detects DNA viruses. To enhance sensor consistency compared to previous literature, two distinct types of NHCs were used to minimize challenges associated with non-specific adsorption. Gold electrodes functionalized with TLRs via NHCs have the potential to operate as broad-spectrum biosensors, as evidenced by their ability to identify biological pathogens based on alterations in resistance and pattern recognition.